1. Field of the Invention
The present invention relates to a discharge lamp, a connecting cable that is used when connecting a discharge lamp and a power supply, a light source apparatus that is provided with a discharge lamp, and an exposure apparatus that is provided with this light source apparatus.
2. Description of Related Art
An exposure apparatus, such as a full field exposure type (stationary exposure type) projection exposure apparatus (e.g., a stepper) or a scanning exposure type projection exposure apparatus (e.g., a scanning stepper) that transfers a pattern formed on a reticle (or a photomask and the like) to a wafer (or a glass plate and the like) that is coated with a resist, is used in a lithographic process for fabricating various devices (such as microdevices and electronic devices). An exposure light source apparatus that comprises a combination of a discharge lamp, such as a mercury lamp, and a condenser mirror is used in such an exposure apparatus, and that discharge lamp is held via a prescribed mounting mechanism.
Among conventional light source apparatuses that have a discharge lamp, there is a type that is provided with a cooling mechanism for reducing the effects of heat generation. In one example of a conventional cooling mechanism, cooled air is supplied from an outer surface of one base of the discharge lamp toward an outer surface of another base via an outer surface of a bulb part (e.g., refer to Japanese Patent Application, Publication No. H09-213129). In another example of a known conventional cooling mechanism, a ring-shaped groove part is provided on a base of a discharge lamp, and cooled air is supplied to a bulb part via the groove part and a prescribed air-blowing pipe (e.g., refer to Japanese Patent Application, Publication No. H11-283898).
With the discharge lamp cooling mechanism in the conventional light source apparatus, cool air is blown principally against the bulb part of the discharge lamp, and consequently there is a problem in that the cooling action with respect to the base is small. Also, the discharge lamp has a base on the fixed side and a base on the free end side, and in the case of cooling the base on the free end side using a conventional cooling mechanism, it is necessary to install piping for air blowing and the like around the base, and consequently there is the problem of much of the light from the discharge lamp being blocked.